Re: [PATCH 01/16] Cherry pick a set of patches that enables multifd zero page feature.

[Fabiano Rosas <farosas@suse.de>]

Hao Xiang <hao.xiang@bytedance.com> writes:

> Juan Quintela had a patchset enabling zero page checking in multifd
> threads.
>
> https://lore.kernel.org/all/20220802063907.18882-13-quintela@redhat.com/

Hmm, risky to base your series on code more than an year old. We should
bother Juan so he sends an updated version for review.

I have concerns about that series. First is why are we doing payload
processing (i.e. zero page detection) in the multifd thread. And that
affects your series directly, because AFAICS we're now doing more
processing still.

Second is more abstract but the multifd packet header is becoming just
about small details about pages. We should probably take the time now
and split that into a multifd header and a payload specific header. With
some versioning stuck to them for migration compatibility.

Now, I don't want to block this series due to my idealistic views on the
code base, so I'll keep those aside while reviewing this, but I
definitely think we should look at the big picture before we get too
tangled up.